Roller grinding-mill



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ROLLER GRINDING MILL. No. 255,715. Patented Mar. 28,1882.

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ROLLER @BINDING MILL.r i N0. 255,715. l `PaZGIlB. Mar. 28.1882.

I gfd N. PETERS. Phulo-Lilhogrlphar. Washingwn. D. C. f v

UNITED STATES PATENT OFFICE.

RICHARD BIRKHOLZ, OF MILWAUKEE, WISCONSIN.

ROLLER GRlNDlNG-MILL.

SPECIFICATION forming part of Letters Patent No. 255,715, dated March28, 1882.

Application filed Decc1nber1, 1861.

To all whom z't may concern Be it known that I, RICHARD BIEKHoLz, ofMilwaukee, in the county of Milwaukee and State of Wisconsin, haveinvented certain Improvements in Roller Grinding-Mills, of which thefollowing is a specication.

My invention relates to improvements designed more particularly for usein small or portable mills, although certain of the features areapplicable to mills of large size.

The principal object of theinvention is to produce a mill which shall beexceedingly cheap and simple in construction, in which the accurateadjustment ofthe rolls may be maintained without the useof separateadjustable devices for their opposite ends, and in which the press- -ureapplied between the rolls shall be governed automatically by thehardness of the material passing between them.

.It also has as anobject the production of d nr- 4 able and accurateribbed rolls without incurring the expense of cutting the ribs-thereon,`

-as is now commonly practiced.

The invention consists in the combination of a standard, a hopper-framemounted in bearings on the standard, and a movable roll mountedin undsustained by said frame; in the combination, with the above, of a springapplied to urge the hopper downward; also, in the combination, with theabove-named parts, of a stop device limiting the swinging action of thehopper; also, in various minor details, which will be hereinafterdescribed.

Referring to the accompanying drawings, Figure 1 represents a sideelevation of my improved mill; Fig 2, a rear elevation ofthe same; Fig.3, a vertical central section'of the same on the line a: x, Fig. 2; Fig.4, a trans` verse vertical section on the line y y, Fig. 3 Fig. 5, ahorizontal section on the line .a z, Figs. 1, 2, &c.;Figs. 6, 7, and S,detail sectional views, illustrating thelconstructiou of theroller-bearings.

Referring to the drawings, A represents an uprighttubular standarddesigned to sustain the weight of the entire mill, provided with anenlarged or flanged base and having its upper end divided into twoupright parallel arms, a.

B represents a horizontal shaft mounted `in fixed bearings orboXes inthe arms a of the receive a supply of grain.

(No model.)

vided with a hand-crank or handle," by means of which motion iscommunicated to the machine. When the machine is to be driven`by powerfrom an engine or other motor the shalt l B may be provided, in place ofor in addition to the balance-wheel D, with a driving-pulley to receivea belt or with a driving gear-wheel. 1

E representsa horizontal bolt passed transversely through the upper endsof the standard-arms a above the grinding-roll C, and serving as asupport for the hopper body or casing F, which is pivoted and free toswing upward and downward in a vertical are to a limited extent thereon.The casing F ismade of suitable form and size to completely inclose thetwo grinding-rolls, being adapted to fit closely against their sidel orend faces, and being fashioned at the top into a small hopper or throat,c, throughwhich the grain is delivered between the rolls, and being alsofash ioned at its lower ends beneath the rolls into a meal-receivingchamber provided with an of the rolls and securedtogether by means oftransverse bolts c, as clearly represented in the drawings. In order topermit the swinging motion of the casing, its sides are slotted at thepoints where the stationary shaft B' passes through thesamc, asindicated in Fig. 5 and in dotted lines in Fig. 3. To the upper part ormouth of the casing F a large wooden hopper, Gr, is bolted or otherwiseH represents a second horizontal shaft carrying at its middle the secondgrinding-roll, I, and mounted at its ends in bearings or boxes tiredrigidly in 'the sides of 'the casing F, as plainly represented. It willbe seen that the second roll, I, and its ,shaftarethus supported by thesurrounding casing F, and that as the casing swings upon the bolt E froma point above the first grinding-roll the downward movement of thecasing serves to crowd the rolls toward eachother, while on the' othersecured to -parts being slipped endwise over the journals IOO hand itsupward motion serves to separate them, the movable roll I swingingaround a point eccentric to the stationary roll. Motion is communicatedfrom the shaft of the stationary roll C by means of a small outsidepinion, J, through a large gear-wheel, K, to

ythe shaft of the second or movable roll, I.

Under the arrangement shown it will be seen that the weightof theeasing, the second roll and its'V shaft, the hopper, the materialcontainedin the hopper, the strain ofthe gears, and the strain which theroll C may exert through the intermediate material upon the roll I alltend to urge the casing downward, and thus crowd the rolls toward eachother. It will be readily seen, therefore, that in grinding hardsubstances which offer a great resistance to the movement of the rollsthe movable roll is crowded downward with greater pressure than whengrinding soft material, and that consequently the rolls are urgedtogether with increased force. This action of the rolls in .crowding onetoward the other is in a great measure dependent upon the fact that thetwo rol-ls are driven positively at different surface speeds, the resultbeing that the material e11- tering between the two rolls and offeringaresistance'to their rotation tends to lock them together in such mannerthat the rotation of V the stationary rolls tends to turn the movablerolls and the support downward. Owing to this action it will be seenthat the mill is in a ydegree automatic or self-adjusting as regards thepressure applied to force the rolls together, vthe rolls being crowdedtogether with agreater 'force when grinding hard material than when ablemanner; but I prefer, as shown in the drawings, to pivot to the lowerend ofthe casing a bolt, J, passing transversely through the standard A,and bearingon its rearend a nut, l, and a washer acted upon by a spiralspring,

Je, seated within the standard around the bolt,

as plainly represented in Figs. 8 and 4. By adjusting the nut thetension of the spring may be increased and the pressure between therolls augmented to any extent required.y

- vIn place of the nut, any other suitable device may be employed as ameans of adjusting the spring.

-The device represented in the drawings con- '.sists simply ofa screw,M, inserted through the standard A, and arranged to encounter a lug orstud on the under side of the hopperframe. In order to prevent thescrewM from beingjarred out of adjustment by the vibration of themill,the jam-nut N is applied, as shown inthe drawings.

In practice I find the most convenient receptacle for the chop or gristto be an ordinary sack, and in order to holdsuch receptacle in positionbeneath the delivery-spout d, I connect to the standard by a bolt, o, ahorizontal ring. P, provided on the inside with a series of smallupturned hooks or teeth, m, adapted to engage with the edge of the bagand to sustain its mouth in an open position beneath the spout. In placeof the teeth, any other fastening devices may be used.

Inasmuch as nails, stones, and other foreign matters ot'refractory'character are liable to tind their way into the mill andendanger breakage of the parts, the bolt E is constructed of such sizeand strength in relation to the other parts of the mill that it willgive way before the other parts receive a dangerous strain. Thisbreakage ofthe bolt will permit the hopper-frame to fall t'o a limitedextent and throw the movable roll away from the roll C,

thus avoidingthe danger of serious injury to Y the mill. When thebreakage of the parts occurs thehopper-framewillbe sustained andprevented from falling bythe shaft ot' the roll B.

The roll shafts orjournals may bc mounted in boxes or bearings of anysuitable construction; but it is desirable that these boxes shall beadjustable to compensate for wear-that they should be readily removablein order that they may be replaced by others when badly worn. I preferto make use of cylindrical bearings or boxes, such as represented inFigs. 4 and 5, each bearing R consisting merely ot' a tube or sleeveslipped around the shaft closely into a seat in the side of the support,and secured by means of a set-screw, S, tapped into the support, andbearing at the inner end in a groove encircling the box or bearing. Thebearings of the movable roll are supported in the hopper-frame, and thebearings of the stationary roll mounted in the arms of the standard A.

In order to afford the long and solid support for the boxes orbearin gs,the support is provided with outside hubs or bosses to receive them, asplainly represented. By making the boxes of cylindrical form andinserting them in the manner described, their read yv rotation at willis permitted, so that the wear may be equalized upon their innersurfaces. Instead, however, of seating the boxes or bearings of thestationary roll D in bosses formed upon the support, as above described,the parts may be constructed as shown in Figs. 6 and 7, in which it willbe seen that the boxes are seated in recesses in one side of thestandard-arms a, and secured therein by clamp-plates T, fastened bybolts. By loosening the bolts the rotation or removal ot' the box ispermitted. This arrangement also permits the introduction of thin sheetmetal at any point outside of the IOO IIO

box, thus permitting the box `and shaft to be A accurately adj usted, asrequired. This feature will be found of great value and convenience :inthe event of the parts being j arred. slightly out of line, asfrequently occurs in practice.

In order to keep the bearings properly lubricated, I cast upon theoutside of the casing and the standard, respectively, oil-reservoirs U,and insert a wick from said reservoir inward to the respeetivejournal,as plainly represented in Fig. 6, suitable holes being cored, ot'course, for the admission of the wick.

In the course ot' a long experience in the 0peration of roller-mills Ihave found it extremely difticult to insure an exact parallelism of theaxes of the two rolls. In mills as at present p constructed it is, Ibelieve, the universal practice to construct rolls of a length usuallyseveral times as great as their diameters. This constructionnecessitates the application of separate adjusting devices to the twoends of each roll. In practice it is found impossible to secure anexactly uniform adjustment of the pressure devices, and consequentlymuch difficulty is experienced on account of the rolls grindingunequally at'the two ends, the mate-- rial being ground liner at one endthan at the other. In order to overcome this difdculty, I construct myrolls ot` a length or breadth considerably less than their diameter, asplainly represented in the drawings, and supporting the two ends of eachroll in one and the same casting. j The single support of the movableroll being arranged to move at right angles to the axis of the oppositeroll, Iam enabled to maintain at all times, and by means of a single setof adjusting devices, an exact uniform space between the two rolls fromend to end, under all adjustments and conditions.

Having thus described myninvention, what I claim is- 1. The combinationof the standard, the roll mounted in fixed bearings in the standard, thehopper-frame pivoted to the standard, and the movable roll journaled inand supported by the hopper-frame, as described and shown, whereby aproper relation is maintained between the hopper and rolls and theweight of the hopper applied to aid in forcing the rolls together.`

2. The combination of thestandard, the roll roll, the swinginghopper-frame, a second roll sustained by the hopper-frame, and a stopdevice, substantially such as shown, to limit the swinging motion of thehopper-frame.

4. The combination ofthe standard, the roll mounted in xed bearingstherein, the hopper` supporting frame having a pivotal connection withthe standard, the second roll sustained by the hopper-frame, the springtending to swing the hopper-frame downward, and an adjustable device,substantially as shown, to limit the movement of the hopper under theaction ot' the spring.

5. In combination with the standard, the stationary roll mountedtherein, and the movable roll, the swinging hopper frame or casingadapted to inclose the two rolls and pivoted to the standard at a pointabove the axes ot' the rolls.

6. The combination of the forked standard, the roller-casing pivoted toand within said standard, and the two grinding-rolls mounted within thecasing and supported one by the standard and the other by the casing,substantially as described and shown.

7. -In combination with the grinding-roll mounted in fixed bearings, thesecond roll mounted in a support which swings from the center above theaxis of the stationary roll, and pinions connecting the two rolls, asshown,

whereby motion is imparted from the first roll to the second and thestrain of the drivingpinion caused to assist in urging the movable rolldownward.

8. The combination of the standard, the tixed roll, the movable roll,the swinging roll-supporting frame encircling the shaft of the stationary roll, and the frame-supporting bolt E, proportioned in relationto the other parts to break or give way when the mill is subjected toexcessive strain.

RICHARD BIRKHOLZ.

i Witnesses:

J. E. WILDIsH, ERICH WESTERNHAGEN.

